A078160 a(n) = A055086(n!).

1, 2, 4, 8, 20, 52, 140, 400, 1203, 3808, 12634, 43771, 157821, 590518, 2287070, 9148286, 37719353, 160029667, 697553152, 3119552536, 14295585635, 67052240163, 321571247089, 1575370942644

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Mathematica

Table[ Length[ Union[ Table[ Floor[w!/j], {j, 1, w!}]]], {w, 1, 11}]

Prog

(PARI) a(n)=sqrtint(4*n! + 1) - 1 \\ Charles R Greathouse IV, Mar 01 2018

Crossrefs

Cf. A055086, A078159, A078161, A078162.

Sequence in context: A358056 A275070 A115219 * A218088 A222320 A089976

Adjacent sequences: A078157 A078158 A078159 * A078161 A078162 A078163

Keyword

nonn

Author

Labos Elemer, Nov 27 2002

Extensions

Extended by Robert G. Wilson v, Dec 02 2002

More terms from Charles R Greathouse IV, Mar 01 2018

Status

approved